Let's divide 1518413 by 999
The aim is to understand the frequency of 999 in 1518413.

Going ahead to step 1:
999 can be fit into 1 0 times, resulting in a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (5) from the dividend to 1 and continue with: 15 / 999

Advancing to step 2:
999 can be fit into 15 0 times, resulting in a remainder of 15.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 15 to get 15.
Fetch the next digit (1) from the dividend, attach it to 15 and continue: 151 / 999

Moving on to step 3:
999 can be fit into 151 0 times, resulting in a remainder of 151.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 151 after subtracting 0 from 151.
Append the next digit (8) from the dividend to 151 and continue with: 1518 / 999

On to step 4:
If we divide 1518 by 999, we get 1 and a remainder of 519.
The next digit of our result is 1. 
Result so far: 1.0
Subtracting 999 from 1518 leaves us with 519.
Take the next digit (4) from the dividend and append it to 519, then repeat: 5194 / 999

On to step 5:
When dividing 5194 by 999, we get 5 with a remainder of 199.
Put 5 as the next digit of the answer. 
Result so far: 15.0
Subtract 4995 from 5194 to get 199.
Bring next digit (1) of the dividend behind the 199 and repeat the process: 1991 / 999

Advancing to step 6:
999 can be fit into 1991 1 times, resulting in a remainder of 992.
Record the quotient 1 as the next digit in the result. 
Result so far: 151.0
Deduct 999 from 1991 and we're left with 992.
Include the next digit (3) from the dividend after 992, then repeat: 9923 / 999

Let's proceed to step 7:
999 can be fit into 9923 9 times, resulting in a remainder of 932.
Put 9 as the next digit of the answer. 
Result so far: 1519.0
Subtracting 8991 from 9923 leaves us with 932.
Since there are no more digits in the dividend, we add a zero to the remainder making it 9320, and continue the process.

Let's proceed to step 8:
If we divide 9320 by 999, we get 9 and a remainder of 329.
Put 9 as the next digit of the answer. 
Result so far: 1519.9
Subtract 8991 from 9320 to get 329.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3290, and continue the process.

Let's proceed to step 9:
When dividing 3290 by 999, we get 3 with a remainder of 293.
Write down 3 as next digit of the result. 
Result so far: 1519.93
Deduct 2997 from 3290 and we're left with 293.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2930, and continue the process.

Moving on to step 10:
When dividing 2930 by 999, we get 2 with a remainder of 932.
Write down 2 as next digit of the result. 
Result so far: 1519.932
Subtracting 1998 from 2930 leaves us with 932.
Since there are no more digits in the dividend, we add a zero to the remainder making it 9320, and continue the process.

Moving on to step 11:
The number 999 fits into 9320 9 times, leaving a remainder of 329.
Write down 9 as next digit of the result. 
Result so far: 1519.9329
If we take 8991 away from 9320, we end up with 329.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3290, and continue the process.

Moving on to step 12:
999 can be fit into 3290 3 times, resulting in a remainder of 293.
The number 3 becomes the next digit in our result. 
Result so far: 1519.93293
Subtracting 2997 from 3290 leaves us with 293.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2930, and continue the process.

On to step 13:
999 goes into 2930 2 times with a remainder of 932.
The number 2 becomes the next digit in our result. 
Result so far: 1519.932932
Subtract 1998 from 2930 to get 932.
Since there are no more digits in the dividend, we add a zero to the remainder making it 9320, and continue the process.

Going ahead to step 14:
9320 divided by 999 is 9 with a remainder of 329.
Write down 9 as next digit of the result. 
Result so far: 1519.9329329
Subtract 8991 from 9320 to get 329.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3290, and continue the process.

Going ahead to step 15:
3290 divided by 999 is 3 with a remainder of 293.
Use 3 as the next digit of our solution. 
Result so far: 1519.93293293
If we subtract 2997 from 3290, we get 293.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2930, and continue the process.

After the division, we end up with 1519.93293293 and a remainder of 2.93e-07.